Hypertension, or high blood pressure, is a serious health issue in many countries. According to the National Heart Blood and Lung Institute, it is thought that about 1 in 3 adults in the United States alone have hypertension. Left unchecked, hypertension is considered a substantial risk factor for cardiovascular and other diseases including coronary heart disease, myocardial infarction, congestive heart failure, stroke and kidney failure. Hypertension is classified as primary (essential) hypertension or secondary hypertension. Primary hypertension has no known cause and may be related to a number of environmental, lifestyle and genetic factors such as stress, obesity, smoking, inactivity and sodium intake. Secondary hypertension can be caused by drug or surgical interventions or by abnormalities in the renal, cardiovascular or endocrine system.
A number of antihypertensive drugs are available for treating hypertension. Various therapeutic classes of antihypertensive drugs include alpha-adrenergic blockers, beta-adrenergic blockers, calcium-channel blockers, hypotensives, mineralcorticoid antagonists, central alpha-agonists, diuretics and rennin-angiotensin-aldosterone inhibitors which include angiotensin II receptor antagonists (ARB) and angiotensin-converting enzyme (ACE) inhibitors. Angiotensin-converting enzyme (ACE) inhibitors inhibit angiotensin-converting enzyme (ACE), a peptidyl dipeptidase that catalyzes angiotension I to angiotension II, a potent vasoconstrictor involved in regulating blood pressure.
Amlodipine is a calcium channel blocker. It affects the movement of calcium into the cells of the heart and blood vessels. As a result, amlodipine relaxes blood vessels and increases the supply of blood and oxygen to the heart while reducing its workload. The structural formula of amlodipine is as follows:

Amlodipine is currently administered in the form of oral tablets, (e.g., Norvasc) or in the form of a refrigerated liquid formulation. In addition to the treatment of hypertension, amlodipine tablets have been used for coronary artery disease (CAD) such as chronic stable angina, vasospastic angina, or angiographically documented coronary artery disease in patients without heart failure or an ejection fraction<40%.